This invention relates generally to a timing device and more particularly to a new and novel single chip microcomputer timer for use in conjunction with a coin-operated device and other exterior devices such as car washers, air dispensing machines, pay showers, suntan salons, vacuum equipment and the like.
Mechanical, electronic and combination timing devices have been in use for many years as evidenced by U.S. Patent Office class 194, subclasses 9, 16 and 18. Such devices are designed to turn on and off exterior devices after insertion of a coin or coins in a coin-operated device.
Add and subtract counters are also known as evidenced by U.S. Pat. No. 2,735,005 issued on Feb. 14, 1956 to F. G. Steele and assigned to Northrop Aircraft, Inc. of Hawthorne, California. Such counters are used in digital computers and count up and down depending on the sign of the pulse fed into the counter.
Electronic coin totalizers are known as evidenced by the U.S. Pat. No. 3,279,480 issued on Oct. 18, 1966 to J. R. JARVIS and assigned to Meter-All Mfg. Co., Inc. of Dallas, Texas. Devices such as this accept coins of different denominations and when the value of the deposited coins accumulates to a certain sum, then a signal is generated to initiate an operation of a coin-operated machine.
Coin actuated timers with audio output are taught in the U.S. Pat. No. 4,176,739 issued on Dec. 4, 1979 to Edward J. Corcoran. This timer provides an audio output at the end of a predetermined time period selected by the user and is responsive to coins inserted into the apparatus.
A coin-operated, elapsed timer is taught in the U.S. Pat. No. 4,541,519 issued on Sept. 17, 1985 to Vinent Belviso et al and represents the closest prior art uncovered by the applicant in his prior art search. This timer is capable of receiving additional coins at any time while counting down and continuously displays the time remaining on the timer and gives a warning at a predetermined time, that the set time has run out.
In the preliminary examination of this patent application by the U.S. Patent Office, the U.S. Pat. Nos. 4,640,624 and 4,367,051 were cited. The device taught in Pat. No. 4,640,624 issued to Peter N. E. Pitt on Feb. 3, 1987, is an electronic timer computer used by road race runners which indicates cumulative time and other times useful to the runner. The device taught in Pat. No. 4,367,051 issued to Akigoro Inoue on Jan. 4, 1983, is a relative time interval measuring instrument capable of simultaneously measuring a plurality of time intervals and providing displays of differences between the shortest one and the others along with their ranking.
Programmable microcontrollers are known in the art as evidenced by the advertising literature from EDN Magazine, Pages 135-138, dated Nov. 27, 1986. The microcontroller HD63701XOP used in the applicant's new and novel timer is distributed by Hitachi America, Ltd., Semiconductor and IC Division, 2210 O'Toole Avenue, San Jose, CA 95131.